Adaptive exercise device with variable components of motion

ABSTRACT

An adaptive exercise device is configured and operable to mechanically decouple the vertical and horizontal components of a user&#39;s foot and leg motion so as to allow the user to independently control the magnitude of both components of motion during the use of the device. The device includes a primary guide assembly which provides for foot motion along a path of travel having equal and opposite, selectably variable, horizontal components of motion and a secondary guide assembly which includes a crankless reciprocating control system which provides for foot motion along respective second paths of travel having equal and opposite, selectably variable, vertical components of motion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of U.S. Provisional Patent Application 61/606,568 filed Mar. 5, 2012, and U.S. Provisional Patent Application 61/625,279 filed Apr. 17, 2012, the disclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to exercise devices which simulate a running and stepping motion. In particular, the invention relates to an adaptive exercise device configured and operable to mechanically decouple the vertical and horizontal components of the foot and leg motion so as to allow a user to independently control the magnitude of both components of motion during the use of the device.

BACKGROUND OF THE INVENTION

There are a variety of exercise devices which attempt to simulate a running and stepping motion in which a user's feet and legs travel along a path having both vertical and horizontal components of motion. One group of such devices is termed “adaptive exercise devices” and such devices decouple the vertical and horizontal components of motion so that the horizontal component of foot and leg motion is independent of the vertical component of the motion of the foot and leg. In this manner, a user can implement a solely vertical foot and leg motion, a solely horizontal foot and leg motion, or a foot and leg motion which is a blended ratio of the two components. Systems of this type are known in the prior art, and one shortcoming of such prior art systems is that their mechanical construction mandates that the vertical component of the leg motion, even though decoupled from the horizontal component of foot motion, be of fixed magnitude. As such, these systems operate in an “all or nothing” mode with regard to vertical motion, and this limits the range through which a user's feet and legs may be exercised. Devices of this type are shown in U.S. Pat. No. 7,179,201.

As will be explained in detail hereinbelow, the present invention provides an improved adaptive exercise device which not only decouples vertical and horizontal components of foot and leg motion but also allows each of these components of motion to be independently varied in magnitude. As a result, the device of the present invention greatly expands the exercise options available to a user.

BRIEF DESCRIPTION OF THE INVENTION

Disclosed is an adaptive exercise device which includes a frame which is configured to be supported on a floor. The device also includes a first and a second foot link each of which has a foot pad portion defined thereupon and configured to receive a user's foot. The device includes a primary guide assembly which engages the foot links and is configured and operable to direct the foot pad portions of the foot links along respective first paths of travel having equal and opposite, selectably variable, horizontal components of motion. The device includes a secondary guide assembly which includes a crankless reciprocating control system which is in mechanical communication with the foot links and is operable to reciprocate the foot links along respective paths of travel having equal and opposite, selectably variable, vertical components of motion. In the use of the device, the magnitude of the motion of the foot pads along the first paths of travel is mechanically independent of the magnitude of the motion of the foot pads along the second paths of travel.

In specific embodiments, the secondary guide assembly of the adaptive exercise device includes a first and a second secondary track pivotally supported at a pivot point defined upon the frame, and the reciprocating control system is operative to reciprocate the first and second secondary tracks about the pivot point along respective paths of travel having equal and opposite vertical components of motion; and in such embodiments, the foot links each engage a respective one of the first and second secondary tracks so as to be displaceable along the length thereof so that when the reciprocating control system reciprocates the secondary tracks along their respective paths of travel having the vertical component of motion, said vertical component of motion is communicated to a respective foot link so as to reciprocate the foot pad portion thereof along the second path of travel having the vertical component of motion. In some such embodiments, the secondary tracks may include an at least partially curved surface which engages a respective foot link.

In particular embodiments, the reciprocating control system may include one or more members selected from the group consisting of pulleys, springs, cables, rocker arms, and the like. In certain embodiments, the primary guide assembly may include a first and a second swing arm each of which is pivotally supported on the frame so that each swing arm is engaged in mechanical communication with a respective one of the foot links so as to at least partially support the foot links as they move along the first path of travel. In such embodiments, the swing arms may be mechanically coupled to their foot link either directly or via a connecting link. In other embodiments, the primary guide assembly may also include at least one primary track which is configured and operative to engage and direct the first and second foot links along the first path of travel.

In specific embodiments, the device may include one or more resistance devices in mechanical communication with the primary guide assembly and/or the secondary guide assembly. Such resistance devices may comprise one or more of a fan device, a frictional brake device, a fluidic device, a magnetic device, a pendulum, a flywheel, and a resilient member.

In another group of embodiments, the reciprocating control system may include an oscillating arm device which includes a first and a second arm coupled thereto so that said arms are pivotally supported so as to be movable in equal and opposite directions relative to the frame of the device. In these embodiments, each arm of the oscillating arm device is coupled to a respective one of the foot links so as to reciprocate that foot link and its associated foot pad portion along the second path of travel having the vertical component of motion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic depiction of one embodiment of adaptive exercise device in accord with the present invention;

FIGS. 2A-4B illustrate some specific crankless, reciprocating control systems which may be utilized in the practice of the present invention;

FIG. 5 shows an alternative foot link arrangement utilized in connection with another embodiment of exercise device in accord with the present invention;

FIG. 6 shows another embodiment of adaptive exercise device in accord with the present invention;

FIG. 7 shows yet another embodiment of adaptive exercise device in accord with the present invention;

FIGS. 8A and 8B show alternative variations of primary guide assemblies which may be utilized in the practice of the present invention;

FIG. 9 shows another embodiment of adaptive exercise device of the present invention in which the foot links thereof are directly reciprocated by a reciprocal controller of the secondary guide assembly;

FIG. 10 is a schematic depiction of another adaptive exercise device of the present invention;

FIG. 11 shows some various paths of motion which may be achieved through the use of an adaptive exercise device of the present invention;

FIG. 12 shows yet another embodiment of an adaptive exercise device in accord with the present invention including an oscillating arm assembly;

FIG. 13 is an end view of the oscillating arm assembly of FIG. 12;

FIG. 14 shows the exercise device of FIG. 12 in a first position in which foot motion is essentially along a path having a primarily horizontal component of motion;

FIG. 15 is an end view of the oscillating arm assembly as positioned with regard to FIG. 14;

FIG. 16 shows the adaptive exercise device of FIG. 12 in a second position in which foot motion is essentially along a path of travel having a primarily vertical component of motion;

FIG. 17 is an end view of the oscillating arm assembly as positioned with regard to FIG. 16;

FIGS. 18A-18C show some particular resistance devices as incorporated into the oscillating arm assembly of the FIG. 12 device; and

FIG. 19 shows another embodiment of an adaptive exercise device of the present invention having a reciprocal controller which includes an oscillating arm assembly.

DETAILED DESCRIPTION OF THE INVENTION

The present invention may be implemented in a number of different configurations and will be explained with regard to some specific embodiments. It is to be understood that other modifications and variations are within the scope of this invention and will be readily apparent to those of skill in the art in view of the teaching of this disclosure.

The device of the present invention operates to simulate a running and stepping motion and includes a frame which is configured to be supported on a floor or other such support surface. The device further includes a first and a second foot link, each having a foot pad portion which receives and supports a user's foot. A primary guide assembly engages the foot links and directs the foot pad portions along a first path of travel having a horizontal component of motion and a secondary guide assembly is in mechanical communication with the foot links and reciprocates them along respective paths of travel having equal and opposite vertical components of motion. The device is configured so that the magnitude of both the horizontal and the vertical component of motion communicated to the foot links may be readily and independently varied by a user in the course of employing the apparatus.

Prior art adaptive exercise devices utilize a crank-based mechanism for controlling the vertical and/or horizontal components of foot motion; and in accord with the present invention, it has been found that the circular component of the crank motion mandates that any reciprocating motion of the user's foot which is dependent on the crank-based mechanism be of a fixed and predetermined value. Hence, prior art adaptive exercise devices, while allowing a user to control the horizontal component of foot motion, restrict a user's foot to a vertical path of travel which is either zero or of a fixed length.

A further shortcoming of crank-based control systems is that crank linkages inherently produce a “dead spot” from which it is difficult to initiate motion, thereby interfering with the smoothness of the foot motion which they provide. As will be explained hereinbelow, the present invention utilizes a crankless linkage to reciprocate a user's foot in the vertical and/or horizontal direction. While devices of the present invention are crankless with regard to the guide elements which reciprocate a user's foot in a vertical and/or horizontal direction, it is possible the adaptive exercise devices of the present invention may include crank elements in conjunction with portions of the device not directly operative to provide a variable, reciprocal foot motion.

Referring now to FIG. 1, there is shown one embodiment of adaptive exercise device in accord with the present invention. The device includes a frame 12 which supports the remainder of the apparatus on a floor or other such support surface. The device further includes a first 14 a and a second 14 b foot link each of which is configured to support a user's foot on a foot pad portion thereof. The foot links 14 a, 14 b are in communication with a primary guide assembly which directs the foot links along a first path of travel having a horizontal component of motion. In this instance, the primary guide assembly comprises a first swing arm 16 a and a second swing arm 16 b which are pivotally supported on the frame 12 and connected to their respective foot links. As will be understood in the art, the swing arms 16 a, 16 b will typically be mechanically coupled together so as to move in equal and opposite paths of travel. Such coupling mechanisms may include gearing arrangements.

The device of FIG. 1 further includes a secondary guide assembly which is in mechanical communication with the foot links 14 a, 14 b and which operates to reciprocate them along respective paths of travel having equal and opposite vertical components of motion. In the FIG. 1 embodiment, the secondary guide assembly includes a first and a second secondary track 18 a, 18 b which are pivotally supported on the frame 12 at a pivot axis 20 defined thereupon. The secondary guide assembly further includes a reciprocating control system (not shown in FIG. 1) which reciprocates the first and second tracks 18 a, 18 b about the pivot axis 20 in the direction generally shown by arrow A. This reciprocal, pivotal motion of the tracks 18 a, 18 b has a substantially vertical component of motion which in turn is communicated to the foot links 14 a, 14 b. Furthermore, the foot links 14 a, 14 b engage their respective secondary tracks 18 a, 18 b by rollers 22 a, 22 b which, in addition to supporting the foot links on the secondary tracks, allow the foot links to move there along in a path of travel having a substantially horizontal component as shown by arrow B. In this manner, the vertical and horizontal components of motion are decoupled. Furthermore, the magnitude of the vertical component of motion of the secondary control system and associated track is not fixed, as is the case with prior art crank wheel based control systems. The crankless control system of the present invention allows for a user to choose an appropriate degree of vertical motion while the device is in use. As will be explained in detail hereinbelow, the reciprocating control system of the secondary guide assembly is configured so that the vertical motion selected by the user is imparted equally and oppositely to each of the foot links.

There are a variety of configurations in which the reciprocating control system of the present invention may be implemented, with the primary requirement being that the system provides equal and opposite vertical motion over a user-selected range of values. Such control systems may be implemented utilizing mechanical components such as pulleys, springs, elastic bodies, cables, rollers, rocker arms, and the like as well as through the use of fluidic devices such as hydraulic or pneumatic cylinders, dampers, pistons, and the like. Referring now to FIG. 2A, there is shown a portion of an exercise device in which a crankless, reciprocating control system comprises a pulley 24 operating in conjunction with a cable 26 so as to raise and lower components of the device which may comprise secondary tracks 18 a, 18 b or foot links, depending on device configuration. FIG. 2B shows an end view of this embodiment of reciprocating control system.

FIGS. 3A and 3B show side and end views respectively of another reciprocating control system in accord with the present invention. This system is based upon the use of two fluidic devices such as hydraulic or pneumatic cylinder/piston arrangements. As will best be seen from FIG. 3B, two cylinders 28 a and 28 b are coupled together so that compression of a liquid or gaseous fluid in one cylinder will be communicated to the other cylinder driving it in an equal and opposite direction, and this motion is again conveyed to further elements of the apparatus such as foot links or secondary tracks 18 a, 18 b. As further seen in FIG. 3A, a pair of springs 30 a, 30 b or other such resilient elements optionally may be incorporated into the apparatus so as to better coordinate the motion of the two elements.

Yet other configurations of reciprocating control systems may be implemented, and one such embodiment is shown in FIGS. 4A and 4B. As shown in FIG. 4A, a pair of cables 32 a, 32 b joins foot links or secondary tracks 18 a, 18 b to corresponding rocker arms 34 a, 34 b which are supported on the frame 12 of the device. The cables 32 a and 32 b are also coupled to a reciprocating arm 35, which is shown in an end view in FIG. 4B. The motion of the reciprocating arm 35 raises and lowers the cables 32 a and 32 b, causing them to raise and lower their respective rocker arms 34 a and 34 b, thereby reciprocating the secondary tracks 18 a and 18 b. As will be understood, yet other embodiments of reciprocating control systems may be implemented utilizing equivalent components, and such will be apparent to those of skill in the art in view of the teaching presented herein.

In the context of this disclosure, the primary guide assembly is described as functioning to direct the foot links along respective first paths of travel having equal and opposite, selectably variable, horizontal components of motion, and the secondary guide assembly is described as functioning to direct the foot links along respective first paths of travel having equal and opposite, selectably variable, vertical components of motion. It is to be understood that these paths of travel may not be precisely equal, owing to play in the mechanical components of the control systems, geometric factors, such as the inclination of the foot links in the use of the device, kinematic factors of the user's motion, and the like. Hence, the term “equal” is understood to allow for some minor variation in respective lengths, provided that the opposite paths are substantially similar.

Referring now to FIG. 5, there is shown yet another embodiment of exercise device in accord with the present invention. Specifically shown is an alternative foot link arrangement in which foot links are joined to their respective swing arms 16 a, 16 b by links 38 a, 38 b. As in the previous embodiment, the secondary guide assembly includes secondary tracks 18 a, 18 b which are pivotally supported upon the frame 12. As discussed, a crankless, reciprocating control system operates to move the secondary tracks in a vertical path of travel.

Referring now to FIG. 6, there is shown another embodiment of the present invention in which the primary guide assembly incorporates a primary track 40 which engages the foot links 14 a, 14 b by rollers 42 a, 42 b. As in the previous embodiment, the secondary guide assembly includes secondary tracks 18 a, 18 b which are pivotally supported on the frame. A reciprocating control system 50, which may be in accord with the description herein, serves to reciprocate the secondary tracks 18 a, 18 b. As will be seen, the foot links 14 a, 14 b engage the secondary tracks 18 a, 18 b by rollers 52 a, 52 b.

Referring now to FIG. 7, there is shown another embodiment of device generally similar to that of FIG. 1, except that the secondary guide assembly includes a pair of curved tracks 54 a, 54 b which are joined together in a parallel relationship by tie rods 56 a, 56 b. These tie rods are in turn pivotally supported so as to be free to rock in a back-and-forth motion such that tracks 54 a, 54 b are reciprocated in complementary up-and-down motions. This reciprocation is implemented utilizing a reciprocating control system shown generally at reference numeral 50. As in the previous embodiment, the primary control system is implemented utilizing swing arms. As further will be seen from FIG. 7, a spring, elastic member, flexible rod, or other such resilient body may be incorporated into the device so as to provide resistance with regard to the primary control system, and hence the horizontal component of motion of the foot links. As specifically shown, a spring 58 is disposed to anchor the swing arm 16 to the frame 12. As will be understood, this element could be otherwise configured and/or placed.

While FIG. 7 shows a first resistance device 58, in mechanical communication with the primary guide assembly, for providing resistance in connection with the horizontal component of motion of the foot links, it is to be understood that a second resistance device may also be included in mechanical communication with the secondary guide assembly. This second resistance device will function to provide resistance with regard to the vertical component of motion of the foot links. Resistance devices may be utilized with any and all embodiments of this invention. The first and second resistance devices may be identical or they may differ, and they may, by way of example and not limitation, comprise flywheel assemblies, fan devices, frictional brake devices, fluidic devices, and magnetic devices, as well as resilient members as noted above. The resistance devices may be operable to provide a fixed degree of resistance, or they may be adjustable to provide a variable degree of resistance. Inclusion of any resistance device is optional in the practice of the present invention, and it should be noted that in some particular instances, variable resistance devices may be associated with only one of the guide assemblies.

FIGS. 8A and 8B show other variations of the primary guide assembly. In FIG. 8A, foot pads are disposed directly upon tracks 18 a, 18 b which reciprocate about a pivot axis defined by a roller 54 which also permits horizontal motion of the tracks. As in the previous embodiments, vertical motion is imparted to the tracks 18 a, 18 b by a reciprocating control system of the type described herein. The embodiment of FIG. 8B incorporates a primary track 40 as part of the primary guide assembly and allows for horizontal motion of the foot links. As in the previous embodiments, a reciprocating control system, not shown, moves the secondary tracks in the vertical direction.

Referring now to FIG. 9, there is shown another embodiment of the present invention in which the foot links 14 a, 14 b are directly reciprocated by a reciprocal controller 50 of the secondary guide assembly without the use of any secondary tracks. As in the FIG. 1 embodiment, the foot links 14 a, 14 b are moved in a horizontal direction by the swing arms 16 a, 16 b which constitute the primary control system. As noted previously, the reciprocal controller 50 may be variously configured in accord with the teaching presented herein.

Referring now to FIG. 10, there is a schematic drawing of an exercise device of the present invention including a particularly configured reciprocal controller 50. In this embodiment, the controller 50 includes a first rocker arm 60 a and a second rocker arm 60 b which are supported by the frame 12. Each rocker arm 60 a, 60 b contacts a respective secondary track 18 a, 18 b via a roller 62 a and 62 b. As in previous embodiments, the secondary tracks 18 a, 18 b are pivotally supported by the frame. The rocker arms 60 a, 60 b are interconnected via a cable 26 supported by an associated pulley 24. The inclusion of the cable synchronizes the motion of the two secondary tracks 18 a, 18 b so that their motion will be equal and reciprocal.

The FIG. 10 embodiment includes a pair of foot links 14 a, 14 b which, as in the FIG. 1 embodiment, are coupled to respective swing arms 16 a, 16 b which in turn are pivotally supported by the frame 12. The foot links 14 a, 14 b are supported upon respective secondary tracks 18 a, 18 b by associated rollers 22 a, 22 b, as in the FIG. 1 embodiment. However, in the FIG. 10 embodiment, the secondary tracks 18 a, 18 b include curved faces which engage the rollers 22. This curvature operates to provide a camming action which modifies the horizontal motion of the foot links 14 a, 14 b, and by choosing a specific camming surface, a desired profile of foot motion may be selected.

Referring now to FIG. 12, there is shown yet another embodiment of an adaptive exercise device in accord with the present invention. As in the prior embodiments, the device includes a frame 12 which supports at least a portion of the remainder of the apparatus on a floor or other such surface. The FIG. 12 embodiment includes a first and a second foot link which are each configured to support a user's foot typically on a foot pad portion thereof. In the FIG. 12 embodiment, only a single foot link 14 a is shown and it is to be understood that a second foot link 14 b is disposed directly there behind and not visible. The device of FIG. 12 includes a primary guide which is constituted by a pair of swing arms, and in this figure only a single swing arm 16 a is visible and a second swing arm is disposed there behind. As in the previous embodiments, the swing arms 16 are pivotally supported upon the frame 12 and mechanically coupled so as to move in equal and opposite paths of travel. The swing arms 16 are likewise coupled to their respective foot links 14 and operate to direct the foot links along a path of travel having a substantially horizontal component of motion.

The embodiment of FIG. 12 includes a secondary guide assembly which incorporates a crankless reciprocating control system in mechanical communication with the foot links. The reciprocating control system is operative to reciprocate the foot links along respective paths of travel having equal and opposite vertical components of motion which are mechanically independent of the motion of the foot links along the first, horizontal path of travel. In this embodiment, the reciprocating control system includes a pair of cables 26 a, 26 b which are connected to their respective foot links 14. The cables are also connected to an oscillating arm assembly 80 which includes a first arm 82 a and a second arm 82 b which are mechanically coupled together and supported by a journal bearing 84, which in turn is supported upon the frame 12. FIG. 13 is an end view of the oscillating arm assembly 80. As will be seen, the oscillating arm assembly 80 and associated cables 26 a, 26 b cooperate to allow the foot links 14 to pivot at their connection points to their respective swing arms 16 so as to move the foot pad portion of the foot link along a path of travel having a substantially vertical component. It will be further appreciated that the nature and construction of the reciprocal control system provides for motion which is independent of the fore and aft motion provided by the primary control system and is also variable in terms of magnitude, while being equal and opposite with regard to each of the foot links. In this manner, vertical and horizontal components of foot motion are independently variable over a user-selected range of motion.

FIG. 14 shows the device of FIG. 12 in a first position in which foot motion is essentially along a path having a primarily horizontal component of motion. In this regard, the primary control system constituted by the arm links 16 a and 16 b is operative to move the respective foot links 14 a, 14 b along a fore-aft path. In the FIG. 14 configuration, the reciprocal control system is not operating to provide any vertical motion to the foot links; however, it will be noted that the cables 26 a, 26 b assist in supporting the foot links while allowing fore-aft motion. FIG. 15 is an end view of the device better illustrating the position of the oscillating arm assembly 80.

FIG. 16 shows the device of FIG. 12 in a mode of operation in which the reciprocal controller of the secondary control system is operative to provide for motion of the foot links 14 a, 14 b along a path of travel having a primarily vertical component of motion. In this regard, the oscillating arm assembly 80 has pivoted about its support point in the journal bearing 84 so that the first arm 82 a thereof is in a substantially vertical orientation and has correspondingly raised the first foot link 14 a. Likewise, the second arm 82 b is in a substantially horizontal orientation and has lowered the second foot link 14 b. Given the coupling of the foot links via the oscillating arm assembly, it will be appreciated that the motion of the foot links along a vertical path will be equal and opposite, and the magnitude of this motion may be selectably controlled by the user. It will thus be appreciated from a review of FIGS. 14-17 that a combination of vertical and horizontal foot motion may be selectably controlled by the user so as to provide various combinations of foot travel.

The device of FIGS. 12-17 may also be configured to incorporate one or more resistance devices in combination with the reciprocating control system. For example, as shown in FIG. 18A, the device may include fluidic cylinders 28 a, 28 b such as hydraulic cylinders or pneumatic cylinders; and as is known in the art, these cylinders may be made adjustable so that the degree of resistance can be varied. As shown in FIG. 18B, the device may similarly include resilient bodies such as springs 30 a, 30 b, as well as elastic bands, flexible members, and the like. As shown in FIG. 18C, the device may also incorporate a pendulum 88 which will provide for kinetic resistance. As shown, the pendulum may be configured so that its weight is adjustable. Other variable resistance devices such as flywheels, frictional devices, magnetic devices, fans, and the like may likewise be incorporated. While the resistance devices of FIGS. 18A-18C are shown as being in direct mechanical engagement with the oscillating arm assembly 80, it is to be understood that they may be otherwise disposed.

Referring now to FIG. 19, there is shown yet another embodiment of an adaptive exercise device in accord with the present invention. The embodiment of FIG. 19 is generally similar to the embodiment of FIGS. 12-17 previously discussed; however, in this embodiment the oscillating arm assembly 80 has been moved to the front portion of the apparatus, and the cables thereof 26 a, 26 b are directed to the rear of the device by means of pulleys 90 a, 90 b so as to engage the rear portion of the foot links 14 as in the prior embodiment. In view of this teaching, it will be further appreciated that the reciprocating control system may be otherwise disposed.

The present invention may be implemented in yet other embodiments utilizing other configurations of primary and secondary control systems. For example, the various track members used in the primary and/or secondary control systems may be curved or of some other non-linear configuration. Also, as noted above, other configurations of reciprocal control systems may be utilized in the present invention.

It is to be understood that through the use of the present invention the vertical and horizontal components of foot motion are under completely independent control. In this manner, both vertical and horizontal motion may be varied from zero to full mechanical range of the device. This will allow for foot motion to be varied over a number of different patterns, and some such patterns are shown schematically in FIG. 11.

In view of the teaching presented herein, yet other modifications and variations of this invention will be readily apparent to those of skill in the art. The foregoing drawings, discussion, and description are illustrative of some specific embodiments of the invention but are not meant to be limitations upon the practice thereof. It is the following claims, including all equivalents, which define the scope of the invention. 

1. An adaptive exercise device comprising: a frame configured to be supported on a floor; a first and second foot link, each foot link each being configured to receive a user's foot; a primary guide assembly which engages said foot links and which is configured and operable to direct said foot links along respective first paths of travel having equal and opposite, selectably variable, horizontal components of motion; a secondary guide assembly which includes a crankless reciprocating control system which is in mechanical communication with said foot links and is operable to reciprocate said foot links along respective paths of travel having equal and opposite, selectably variable, vertical components of motion; wherein the magnitude of the motion of said foot pads along said first paths of travel is mechanically independent of the magnitude of the motion of said foot pads along said second paths of travel.
 2. The adaptive exercise device of claim 1, wherein said secondary guide assembly further includes a first and a second secondary track pivotally supported at a pivot point defined upon said frame, and said reciprocating control system is operative to reciprocate said first and second secondary tracks about said pivot point, along respective paths of travel having equal and opposite vertical components of motion, and wherein said foot links each engage a respective one of said first and second secondary tracks so as to be displaceable along the length thereof, so that when said reciprocating control system reciprocates said secondary tracks along their respective paths of travel having said vertical component of motion, said vertical component of motion is communicated to a respective foot link so as to reciprocate said foot pad portion along said second path of travel having said vertical component of motion.
 3. The adaptive exercise device of claim 2, wherein said secondary tracks include an at least partially curved surface which engages a respective foot link.
 4. The adaptive exercise device of claim 1, wherein said reciprocating control system includes at least a member selected from the group consisting of: pulleys, springs, cables, rollers, rocker arms, fluidic devices, and combinations thereof.
 5. The adaptive exercise device of claim 1, wherein said reciprocating control system includes at least two interconnected fluidic devices.
 6. The adaptive exercise device of claim 1, wherein said primary guide assembly includes a first and a second swing arm which are pivotally supported by said frame, each swing arm being engaged in mechanical communication with a respective one of said foot links, wherein said swing arms at least partially support their respective foot links as they move along said first path of travel.
 7. The adaptive exercise device of claim 6, wherein each of said swing arms is mechanically coupled to its respective foot link via a connecting link.
 8. The exercise device of claim 6, wherein said primary guide assembly further includes at least one primary track which is configured and operative to engage and direct said first and second foot links along said first path of travel.
 9. The adaptive exercise device of claim 1, further including a resistance device in mechanical communication with the primary guide assembly and/or the secondary guide assembly.
 10. The adaptive exercise device of claim 9, wherein said resistance device comprises one or more of: a fan device, a frictional brake device, a fluidic device, a magnetic device, a pendulum, a flywheel, and a resilient member.
 11. The adaptive exercise device of claim 1, wherein said primary guide assembly includes a first and a second swing arm which are pivotally supported by said frame, each swing arm being engaged in mechanical communication with a respective one of said foot links, wherein said swing arms at least partially support their respective foot links as they move along said first path of travel; and wherein said reciprocating control system includes an oscillating arm device which includes a first arm and a second arm coupled thereto, said arms being pivotally supported so as to be movable in equal and opposite directions, each arm being coupled to a respective one of said foot links so as to so as to reciprocate said foot pad portion thereof along said second path of travel having said vertical component of motion.
 12. The adaptive exercise device of claim 11, wherein the arms of said oscillating arm device are each coupled to a respective one of said foot links by a cable.
 13. An adaptive exercise device comprising: a frame configured to be supported on a floor; a first and second foot link, each foot link having a foot pad portion configured to receive a user's foot; a primary guide assembly which engages said foot links and which is configured and operable to direct the foot pad portions of said foot links along respective first paths of travel having equal and opposite, selectably variable, horizontal components of motion; a secondary guide assembly which includes a reciprocating control system which is in mechanical communication with said foot links and is operative to direct the foot pad portions of said foot links along respective second paths of travel having equal and opposite, selectably variable, vertical components of motion; wherein the motion of said foot pads along said first paths of travel is mechanically independent of the motion of said foot pads along said second paths of travel so that when the device is in use, the foot motion of a user can have a variable horizontal component of motion, a variable vertical component of motion, or a combination of both. 